Roof construction



April 30g 1940- F. B. WALLACE 2,198,685

ROOF CONSTRUCTION Filed Jan. 9, 1939 TML VWM Patented Apr. 30, 1940 UNITED sfrrvrlas PATENTl OFFICE 6 Claims.

My invention relates to the use of concrete in a roof `construction in which a relatively thin slab of concrete is used `to form a run-off surface for the Water and has a finished structure simulating shingles. There have been patents issued and attempts to make concrete roofs of a somewhat similar thin slab type of formation however difficulties have been experienced in the cracking of the cement as it is almost impossible to prevent the thin material from cracking. However in my construction I make -provlsion for the cracks to develop at specialv and designated thin or weakened places so that such cracks are substantially no detriment to the completed 5 roof. My type of molding or laying of the cemcntto form the simulation `of shingles is quite distinct from concrete or similar roof constructions in which the finished -surface is marked off by lines or similar devices to represent by such markings the outline of shingles.

A further object and feature of my invention is the employment of the concrete roof slabs with the shingle type of upper surface to be applied to a wood construction of roof in which the ordinary type of wood sheeting is laid on the rafters, this having the desired slope. With my oonstruction it is desirable to have a good type of water-proof covering on-the sheeting. There are `many types of constructions suitable for this purpose however it is necessary that this covering is `not perforated by any nail holes or the like which would let water ina rainy period or the water melted from snow seep through to the Wood sheeting. It is also highly desirable that thewater-proof covering be of material which is proof againstrot on account of a certain amount of dampness being retained in the concrete during rainy or damp weather and the material being subject to changes of temperature. n fore recommend either roofing felts with coal tar coating or a roofing having a cap sheet of an asbestos type of felt. Another excellent waterf surface and attached to as few places as possible, thus witha ridge type .of roof the reinforcing wire may be attached adjacent the eaves` and stretch over the` ridge from'one eave to the other I and in a single slopeor` shed `type of roof the I there- Work and it is preferably stretched over the roof` reinforcing wire need only be attached adjacent the top and the eave portion of the roof, thus avoiding nail holes through the `water proofing material.

'Ihe next procedure in constructing my roof 6 is to form a covering for coating designated in the trade as a scratch coat of concrete. 'Ihis embeds the wire reinforcing so that such wire mesh material forms a thorough bonding and reinforcing for the concrete slab forming the R0 scratch coat. This scratch coating is usually somewhat rough on its upper surface and such upper surface is approximately parallel to the wood sheathing underneath.

In the feature of my invention in forming the w simulation of the shingle, these are molded directly on the scratch coat in such a manner that the simulated shingles have the taper with the thin upper edge portion anda thick lower edge, thus giving the pleasing relief of the butt end of 2o shingles. In one procedure I employ a fork shaped mold which starting adjacent the ridge of the roof or the' upper portion is used to molol the successive shingles, these being trowelled oif to a taper and the prongs of the mold forming spaces between adjacent shingles in the same row.

In another form of my invention a form strip is laid on the scratch coat. This is of the olesired thickness to form `the thick base of a shingle. A strip is then trowelled having the desired slope of the shingle surface and to give the appearance of individual shingles I employ grooves usually cut by pressing a blade the same length as the width of the shingle and therefore forming the groove the width of the exposed a5 shingle. Thus a characteristic of the shingle finish is that at each layer of shingles or at each individual shingle there is a weakened or thin section adjacent the thin or upper part of the shingle construction and this is the part that is most likely to crack in any cracking of the cement but these cracks are usually so ilne that they are more or less immaterial so far as leakage of water is concerned. Further, where the individual shingles are molded they are of such small size that `the cracks do not readily develop in the shingle construction itself. In theform in which the grooves are trowelled, these trowel lines form a slight weakening of the shingle slab so that if cracks develop they are produced in 6i) straight lines in alignment with the slope ofthe roof. When the scratch coat is cured to a sumcient degree and the concrete shingles molded thereon.. there` is a proper bond between the shingles ,and the scratch coat. thus forming a 5:54

substantially impervious concrete roof construction over the water-proof composition roong and the wood sheeting.

A characteristic feature of my invention is that the top surface construction simulating shingles is molded from the upper portion of the roof, that is, the portion adjacent the ridge downwardly towards the lower. portion of the roof -to the eave. This is in contradlstlnction to the usual manner of laying shingles. Thus an upper row of the roof surface simulating shingles is formed and then the next lower row with the thin edge of such lower row butting against and bonding with the thick edge of the row above, the surface of each row thus being finished oi or troweled on a slope relative to the roof lesser than that of the roof considered as to a horizontal plane, hence in one form of my invention where I employ a molding tool for each so-called shingle, the parallel tapered prongs of the tool which are connected to a thick base have the blunt ends of the prongs thrust against the lower thick edge of the shingle thereabove, the space between this butt of an upper shingle, the two prongs and the base of the tool are then filled with concrete which is struck off on a line with the upper surface of the prongs and the base thus forming an individual tapered shingle and these are made in successive rows. In another procedure, an upper panel is formed using a mold board which has an edge defining the thick or butt edge of the shingle. The concrete is then filled in between the upwardly facing edge of the mold. board and the lower thick edge of the shingle next above. The panel is tapered as to thickness so that the upper panel presents a reveal edge facing downwardly. The upper panel then may be cut into by score lines running at right angles to the mold board and thus to the length of the panel.

My invention is illustrated in connection with the accompanying drawing in which Figure 1 is a plan of a portion of a roof taken in the direction of the arrow I of Fig. 2,. it being presumed that the roof has the usual slope.

Fig. 2 is a vertical section on the line 2-2 of Figure 1 in the direction of the arrows.

Fig. 3 is a plan of an individual shingle molding tool taken in the direction of the arrow 3 of Fig. 4.

Fig. 4 is a side elevation of the same tool taken in the direction of the arrow 3 of Fig. 3.

Fig. 5 is a plan of an alternative roof construction illustrating a part of the roof taken in the direction of the arrow 5 of Fig. 6.

Fig. 6 is a vertical sectiontaken on the line 6-5 of Fig. 5 in the direction of the arrows.

Referring rst to the construction of Figs. 1 and 2 requiring the use of the tools of Figs. 3 and 4, the roof has a layer of wood boards or sheathing I I, this being an ordinary construction and supported on rafters or the equivalent these not being illustrated. Laid completely over the top of the roof sheathing there is a covering of a waterproofing roof material or composition I2.

This, as above stated, may be made of ordinary roofing felt. It is, however, desirable that it have an adequate coating of tar or equivalent material. A better type of roofing is that which has a cap sheet of asbestos together with the sufiicient amount of asphaltum. In view of the fact that this waterproofing layer is subsequently covered and thus out of contact with the air ex cept such as can seep through the concrete and through the cracks in the sheathing the waterreenforcement material I3. This is illustrated as the convenient wire mesh or similar material such as used in roofing or stucco sidings or the like. Where a ridge type of roof is used, it is desirable to attach the wire or similar reenforcing adjacent the eave of the roof and stretch it completely over the ridge to the opposite eave using as few nails as possible. With a shed-type of roof, the wire may be attached adjacent the upper edge and the eave.

A scratch coat Il of concrete made in suitable l mixture is then covered completely over the wire reenforcement and worked into this so as to completely embed such reenforcement in the scratch coat or concrete. The underside of the scratch coat therefore engages the surface of the water- 2 proofing cover. Such scratch coat may be made and applied in the ordinary manner and is usually left somewhat. rough on its upper surface. It is preferable where possible to mold the shingies prior to the complete setting of the scratch 2 coat.

In Figs. 1 and 2 the shingles designated I3 are `molded by the molding tool 20 illustrated in Figs. 3 and 4. 'I'his tool has a handle 2|, a base molding straight section 22, and opposite tapered 3` prongs 23. The prongs terminate in a thin vertical rectangular edge 24. They are relatively thick at the portion 25 adjacent the base 22. For convenience of manipulation, the handle may be parallel to the upper edge 26 of the prongs, the 3 lower edge 2l then converging from the wide section 25 to the thin edge 24. The shingles or imitation shingles are molded separately, using the molding tool and starting with the row at the high point of the roof. The tool in use is illustrated in dotted lines in Fig. 1.

The ends 24 of the prongs are fitted against a straight surface at the ridge or the edge of previously molded shingles. 'Ihe under edge 21 is placed ilat on top of the scratch coat, then concrete is filled into the mold formed by the prongs 23 and the base 22. 'Ihe surplus concrete is struck oi with a toothed edged tool and is usually left rough. The upper edges 26 of the prongs form a guide in striking oi the upper surface, and level with the upper edges 28 of the prongs of the tool. This construction therefore produces the shingles having the construction of a thin upper edge 30, a thick lower edge 3|. a surface 32 having a slope which is not parallel to the surface of the scratch coat but is manifestly at a slightly less slope in reference to the horizontal. Each individual shingle has an edge line 33 on its opposite edges running in straight lines from the ridge or the upper edge' of the roof. It is preferable to stagger the shingles as illustrated in Figure 1. 'Ihere is a slight space indicated at 34 between the adjacent edges 33 of contiguous shingles. This may be designated as a vertical joint. 05

It will thus be seen that the construction has a complete layer of concreteformed in the scratch coat, the individual shingles each separated by the vertical joint but each row connected to the next adjacent upper or lower row at the thin portion 30 upon the upper edge of each individual shingle. Therefore, should there be cracks developed in the shingle coating they are most likely to occur at the weakened lines adjacent the thick base 3| of each of the shin- 76 arcanes sies. such cracks dc not materially @nuancierY the roof as to leakage of water as auch water will reach the vertical joints I4 and hence now board indicated at 40. Such molding board is` preferably rectangular in cross-section and has at least an upper vertical edge 4l of thesame thickness as the base portion 42 of a row of shingles indicated at 43. The molding of the shingles is started from the upper portion of the roof, the mold board may be placed'and 4located in any desired manner, it being held down on the scratch coat preferably by suitable weights. Ihe mold board, as illustrated, forms a straight lower edge for the shingles. 'Ihese are then troweled so that their upper surface 44 has a lesser slope than that of the upper surface ofthe scratch coat, the upper surface of the mold board y the scratch coat as in Fig. 1. This construction likewise presents the shingles with a weakened portion adjacent the thin upper edge and also weakened vertical lines 45. Hence, should any crack develop in the shingle coating such cracks are most likely to follow the weakened portion. It is obvious that in the construction of Figs. 5 and 6, it is not necessary that the mold board or strip 40 be straight. This could be curved or of other desired shape and thus give a varying length to the different portions of each row of shingles. It will therefore be seen that by my roof construction it has the adequate protecting features of a concreteroof together with the desirable appearance of a shingled roof, the thick butt ends of the shingles giving prominent and shadow lines desired for lthe architectural effect.

It is to be noted by my Lconstruction that the so-called shingles do `not overlap but are molded either as individual shingles in the construction of Figs. 1 and 2 or in rows of panels as in Figs.5 and 6 starting from an upper part of the roof and working down towards the lower portion. The rectangular ends 24 of the prongs of the tool of Figs. 3 and 4 therefore butt against the thick lower edge 3|of the row of shingles abovethat being molded. In the construction of Figs, 5 and 6 the mold board 40 is successively positioned downward on the roof from a row or panel such as 44 on an upper part of the roof. The space then between the mold board and the butt edge of the upper row or panel is then filled with concrete, this being struck off at the lower edge reveal with the mold board and becomes thinner towards the butt end of the panels next above. It will be apparent that this type of construction can be placed on roofs of either a slight or a steep pitch and if desired could even be made on vertical surfaces, the principle of operation from the upper portion downwardly being continued.

' Various changes may be made in the details of the construction without departing from the spirit or scope of the invention as dened by the appended claims. I claim:

Y 1. In the method of forming a` self-hardening composition roof on an under-roof structure comprising molding a panel row of shingles at an upper portion of the roof with the `thick butt edge facing downwardly and the thin upper edge facing upwardly, then forming a lower panel row `of shingles with the upper thin edge hutting against the thick butt edge of the panel row next above, then in successive similar panel rows continuing the covering of the roof, the successive panel rows being molded in a sequence from an next above, then in successive similar panel rows y continuing the covering ofthe roof, the successive panel rows being molded in a sequence from an upper towards a lower portion of the roof, molding each shingle of a panel in a separate mold defining the butt and the two side edges, the upper edge of the individual panel being defined by the butt edge of the panel row next above.

3. In the method of forming a self-hardening composition roof on an under-roof structure comprising molding a panel row of shingles at an upper portion of the roof with the thick butt edge facing downwardly and the thin upper edge facing upwardly, then forming a lower panel row of shingles with the' upper thin edge butting against the thick butt edge of the panel row next above, then in successive similar panel rows continuing the covering of the roof, the successive panel rows being molded in a sequence from an upper towards a lower portion of the roof, molding a panel row by defining the lower butt edge of such panel row and striking oiI the surface of the composition at the desired heighth for such edge and forming the lower panel row each thinner at its upper portion where it abuts the panel row next above.

4. In the method of forming a self-hardening composition roof comprising molding an upper panel row of the composition with a thick butt lower edge facing downwardly on the roof and a thin upper edge towards the upper part of the' roof whereby the upper surface of the panel row has a slope less than that of the roof on which the composition is laid, then continuing molding successively lower panel rows with each panel row having a thick lower edge and a thin upper edge, the upper edge engaging the thick butt edge of the panel next above and bonding therewith.

a thin upper edge towards the upper part of the roof whereby the upper surface of the panel row hasa` slope less than that of the roof on which the composition is laid, then continuing molding successively lower` panel rows with each panel row having a thick lower edge and a thin upper edge. the upper edge engaging the thick butt edge of the panel next above and bonding therewith, in forming each panel row molding individual shingles dened by a thick base and tapered side edges and forming spaces between the adjacent side edges of shingles by spacing the molded shingles in each panel row.

6. In the method of forming a self-hardening composition roof comprising molding an upper panel row of the composition with a thick butt lower edge facing downwardly on the roof and a thin upper edge towards the upper part of the root whereby the upper surface of the panel row has a slope less than that of the root on which the composition is laid, then continuing molding successively lower panel rows with each panel row having a thick lower edge and a thin upper edge. the upper edge engaging the thick butt edge of the panel next above and bonding therewith. molding each `panel row between a mold board and the panel row next above in which the surtace of each panel row is struck off the thickv4ness oi' the mold board and tapers to the thick or butt edge o! the panel next above, the thin 

